Rising numbers of lessons observed by Ofsted are being branded “inadequate”
amid continuing concerns over teaching standards, it has emerged.

Figures published for the first time show that almost one-in-20 lessons seen by inspectors in the last academic year have gained the lowest possible mark.

It was also revealed that at least one-in-10 lessons were inadequate in six local authority areas, compared with none just 12 months earlier.

The disclosure follows the publication of Ofsted’s annual report last year that showed teaching was “still too variable” in English state schools, impacting on pupils’ results and fuelling bad behaviour in the classroom.

Poor teachers relied too heavily on worksheets and a narrow range of textbooks during lessons, it was claimed. They also often spent too long talking, set “low-level” tasks that failed to develop pupils’ knowledge and struggled to mark written work properly, said Ofsted.

The watchdog now wants schools to establish a closer link between teachers’ performance and pay.

Speaking last week, Sir Michael Wilshaw, the chief inspector, sparked controversy when he said that schools should consider blocking pay rises for teachers who persist in being “out the gate at 3 o’clock”.

Ofsted currently observe individual teachers’ lessons and judgments made in the classroom contribute towards overall reports drawn up on schools.

This week, the watchdog published a three-year breakdown of ratings attached to individual lessons following a Parliamentary Question by John Pugh, the Liberal Democrat MP for Southport.

In the last academic year, 70,791 lessons were observed, it was revealed. Thirteen per cent have been given Ofsted’s highest possible rating - "outstanding" - but four per cent were marked “inadequate”, the lowest score. This compares with three per cent a year earlier.

A local authority breakdown showed that at least 10 per cent of lessons gained the lowest possible score in six areas – Windsor and Maidenhead, Luton, Reading, Sandwell and the London boroughs of Bexley and Hammersmith and Fulham.

In 2009/10, one-in-10 lessons were inadequate in just one local authority, while none were marked down in this way in 2010/11.

An Ofsted spokeswoman insisted that the figures were based on a “sample” of lessons, meaning they were “not necessarily representative of the nation as a whole”.

She also pointed out that the inspection process had been overhauled in recent years to focus on weak schools at the expense of those previous rated outstanding.

“Due to proportionate inspection and the deferring of inspection of outstanding schools the summary statistics are likely to underestimate the proportion of outstanding or good teaching and overestimate the proportion of satisfactory or inadequate teaching compared to what we would expect to see if we had observed every lesson across the country,” she said.